SB 12.4.1

śrī-śuka uvāca
kālas te paramāṇv-ādir
 dvi-parārdhāvadhir nṛpa
kathito yuga-mānaṁ ca
 śṛṇu kalpa-layāv api
Synonyms: 
śrī-śukaḥ uvāca — Śrī Śukadeva Gosvāmī said; kālaḥ — time; te — to you; parama-aṇu — (the smallest fraction of time measured in terms of) the indivisible atom; ādiḥ — beginning with; dvi-para-ardha — the two halves of Brahmā’s total life span; avadhiḥ — culminating in; nṛpa — O King Parīkṣit; kathitaḥ — has been described; yuga-mānam — the duration of the millennia; ca — and; śṛṇu — now hear; kalpa — Brahmā’s day; layau — annihilation; api — also.
Translation: 
Śukadeva Gosvāmī said: My dear King, I have already described to you the measurements of time, beginning from the smallest fraction measured by the movement of a single atom up to the total life span of Lord Brahmā. I have also discussed the measurement of the different millennia of universal history. Now hear about the time of Brahmā’s day and the process of annihilation.